Per

clojure.java.process/start returns a reify of ILookup, IDeref, and IBlockingDeref.

The IBlockingDeref implementation is wrong - it just passes the two timeout args from blocking (deref [ref timeout-ms timeout-val]) to Process.waitFor(long timeout, TimeUnit unit). Those don’t match. Also, the return value of the 2-arity Process.waitFor() is a boolean, instead of the exit value returned from the 0-arity, so that is also broken.

Additionally:

• Both impls of deref return boxed Integer, should return Long.

• start should not return an object that is both a value (streams map) and a reference (for waiting). Simply return the Process, and provide a helper exit-ref that can wait for the process and return the exit code on completion.

Approach: Correctly implement the blocking deref arity to always use TimeUnit/MILLISECONDS as the timeout unit, return the timeout value on timeout, and return the exit value on non-timeout.

Change start return, add exit-ref, remove ok? (as it is then just a zero? check on exit-ref). Add stdout stderr and stdin helpers to pull the correct stream from the Process.

Patch: clj-2865-6.patch

Screened by: fogus